title: [Restoring vision in blind patients following photoreceptor degeneration: clinical results and future challenges].
abstract: Retinal prostheses aim at restoring vision in patients blind from photoreceptor degeneration by electrically stimulating the residual retinal tissue. Currently, the most efficient implants are either inserted in the subretinal space or on the vitreal side of the retina (epi-retinal). Although the residual tissue can partly degenerate, it was shown that acute stimulation of residual neurones can induce visual percepts. Recently, a clinical trial with the epiretinal Argus2 device (60 electrodes) from the company 2nd Sight enabled most patients to orient and find light targets, some even reading words. This device has received a CE mark. Surprisingly, when the subretinal implant from the company Retina Implant AG displaying many more electrodes (1500 electrodes) was evaluated in clinical trials, the patient visual performances were fairly similar. The restored visual performances of the patients demonstrate that blind patients can recover some visual function when their residual retina is properly stimulated. However, the resolution is not yet sufficient to perform complex tasks such as autonomous locomotion, face identification or text reading. Several challenges remain to generate an increase in pixel density corresponding to the increase in electrode number and density. These challenges include the stimulation modality, the tissue/implant interface design, the electrode materials, and the visual information encoder. This review will discuss these great challenges after introducing the major clinical results.
authors.affiliation: INSERM, U968, Institut de la Vision, 75012 Paris, France - UPMC Université Paris 06, UMR S968, Institut de la Vision, 75012 Paris, France - CNRS, UMR 7210, Institut de la Vision, 75012 Paris, France.
authors.forename: Amel
authors.initials: A
authors.lastname: Bendali
authors.forename: Henri
authors.initials: H
authors.lastname: Lorach
authors.forename: Milan
authors.initials: M
authors.lastname: Djilas
authors.forename: Olivier
authors.initials: O
authors.lastname: Marre
authors.forename: Ryad
authors.initials: R
authors.lastname: Bensoman
authors.forename: Lionel
authors.initials: L
authors.lastname: Rousseau
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Lissorgues
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Scorsone
authors.forename: Philippe
authors.initials: P
authors.lastname: Bergonzo
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garrido
authors.forename: José Alain
authors.initials: JA
authors.lastname: Sahel
authors.forename: Serge
authors.initials: S
authors.lastname: Picaud
mesh_terms: D001766:Blindness / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D010786:Photoreceptor Cells / Q000502:physiology*; D019736:Prostheses and Implants / Q000639:trends; D011474:Prosthesis Design / Q000379:methods / Q000639:trends; D012038:Regeneration / Q000502:physiology*; D012160:Retina / Q000502:physiology / Q000503:physiopathology; D012162:Retinal Degeneration / Q000503:physiopathology* / Q000628:therapy*; D014785:Vision, Ocular / Q000502:physiology*